App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 134 · 40 questions

Developer's tip (Box, list, place): A variable holds one value; a list holds many in order. Positions start at 0. push adds to the end; pop takes off the last item; length is how many items. On the phone: works offline, private. In the cloud: shared, any device, needs the internet.

1. 1.💾 Where should the app save a class leaderboard: on the phone or in the cloud? (a) in the cloud (b) on the phone
2. 2.💾 What number does this code show?
   let songs = ["Stars", "Sunrise", "Rain", "Monsoon"];
   songs.push("Kites");
   songs.push("Ocean");
   show(songs.length);
3. 3.💾 What number does this code show?
   let friends = ["Arjun", "Meera", "Zoya", "Riya"];
   friends.push("Kabir");
   friends.push("Aman");
   show(friends.length);
4. 4.💾 Which can hold many values in order? (a) a switch (b) a list (c) a button (d) a single number
5. 5.💾 What does this code show? (Positions start at 0.)
   let notes = ["Music", "Hindi", "Sports", "Maths", "Art"];
   show(notes[2]); (a) Hindi (b) Maths (c) Sports (d) Music
6. 6.💾 pop() takes off the last item. What does this code show?
   let notes = ["Hindi", "Science", "Music"];
   notes.pop();
   show(notes[notes.length - 1]); (a) Music (b) Science (c) Hindi
7. 7.💾 pop() takes off the last item. What does this code show?
   let friends = ["Aman", "Arjun", "Kabir", "Riya", "Zoya"];
   friends.pop();
   show(friends[friends.length - 1]); (a) Aman (b) Arjun (c) Riya (d) Kabir
8. 8.💾 What number does this code show?
   let points = 9;
   points = points - 3;
   points = points + 1;
   show(points);
9. 9.💾 Where should the app save a shared to-do list: on the phone or in the cloud? (a) on the phone (b) in the cloud
10. 10.True or false: the sound on/off setting fits saving on the phone. (a) True (b) False
11. 11.True or false: your last game level fits saving on the phone. (a) True (b) False
12. 12.💾 What does this code show? (Positions start at 0.)
    let notes = ["Science", "Art", "Hindi"];
    show(notes[1]); (a) Hindi (b) Art (c) Science
13. 13.💾 pop() takes off the last item. What does this code show?
    let songs = ["Stars", "Rain", "Kites"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Rain (b) Stars (c) Kites
14. 14.Which of these fits saving in the cloud? (a) your last game level (b) notes to read offline (c) chat messages to friends (d) the sound on/off setting
15. 15.💾 What number does this code show?
    let songs = ["Monsoon", "Stars"];
    songs.push("Ocean");
    songs.push("Kites");
    show(songs.length);
16. 16.Which of these fits saving in the cloud? (a) a draft you are typing (b) a class leaderboard (c) your last game level (d) notes to read offline
17. 17.💾 What number does this code show?
    let friends = ["Arjun", "Riya", "Aman", "Meera"];
    friends.push("Zoya");
    show(friends.length);
18. 18.Which of these fits saving on the phone? (a) a shared to-do list (b) the sound on/off setting (c) a class leaderboard (d) chat messages to friends
19. 19.💾 What number does this code show?
    let lives = 7;
    lives = lives - 6;
    lives = lives + 2;
    show(lives);
20. 20.True or false: a draft you are typing fits saving in the cloud. (a) True (b) False
21. 21.💾 Where should the app save notes to read offline: on the phone or in the cloud? (a) in the cloud (b) on the phone
22. 22.💾 What number does this code show?
    let stars = 6;
    stars = stars - 1;
    stars = stars + 1;
    show(stars);
23. 23.Which of these fits saving in the cloud? (a) a shared to-do list (b) the sound on/off setting (c) your last game level (d) notes to read offline
24. 24.True or false: a shared to-do list fits saving in the cloud. (a) False (b) True
25. 25.💾 Data saved only on the phone is lost when ___. (a) the app is closed (b) the screen turns off (c) the phone is lost (d) you send a message
26. 26.💾 What number does this code show?
    let coins = 5;
    coins = coins - 4;
    coins = coins + 1;
    show(coins);
27. 27.💾 What number does this code show?
    let coins = 9;
    coins = coins - 4;
    coins = coins + 1;
    show(coins);
28. 28.True or false: your last game level fits saving in the cloud. (a) False (b) True
29. 29.True or false: notes to read offline fits saving on the phone. (a) False (b) True
30. 30.💾 What number does this code show?
    let stars = 5;
    stars = stars - 1;
    stars = stars + 3;
    show(stars);
31. 31.Which of these fits saving on the phone? (a) a class leaderboard (b) notes to read offline (c) chat messages to friends (d) photos on two devices
32. 32.💾 pop() takes off the last item. What does this code show?
    let songs = ["Stars", "Ocean", "Sunrise", "Rain"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Ocean (b) Sunrise (c) Rain (d) Stars
33. 33.💾 What number does this code show?
    let notes = ["Hindi", "Music", "Maths", "Art"];
    notes.push("Sports");
    notes.push("Science");
    show(notes.length);
34. 34.Which of these fits saving on the phone? (a) a class leaderboard (b) photos on two devices (c) your last game level (d) chat messages to friends
35. 35.💾 What number does this code show?
    let lives = 9;
    lives = lives - 7;
    lives = lives + 4;
    show(lives);
36. 36.True or false: a draft you are typing fits saving on the phone. (a) False (b) True
37. 37.True or false: notes to read offline fits saving in the cloud. (a) True (b) False
38. 38.True or false: photos on two devices fits saving on the phone. (a) True (b) False
39. 39.💾 pop() takes off the last item. What does this code show?
    let notes = ["Hindi", "Music", "Sports"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Hindi (b) Sports (c) Music
40. 40.💾 What number does this code show?
    let coins = 3;
    coins = coins - 1;
    coins = coins + 1;
    show(coins);

Free app development lessons, practice and worksheets at talentjr.in/app-development-for-students